libceph, ceph: change ceph_calc_file_object_mapping() signature

- make it void
- xlen (object extent length) out parameter should be u32 because only
  a single stripe unit is mapped at a time

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
5 files changed